src/lib/CECInputBuffer.h

   1 #pragma once
   2 /*
   3  * This file is part of the libCEC(R) library.
   4  *
   5  * libCEC(R) is Copyright (C) 2011-2013 Pulse-Eight Limited.  All rights reserved.
   6  * libCEC(R) is an original work, containing original code.
   7  *
   8  * libCEC(R) is a trademark of Pulse-Eight Limited.
   9  *
  10  * This program is dual-licensed; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  *
  25  * Alternatively, you can license this library under a commercial license,
  26  * please contact Pulse-Eight Licensing for more information.
  27  *
  28  * For more information contact:
  29  * Pulse-Eight Licensing       <license@pulse-eight.com>
  30  *     http://www.pulse-eight.com/
  31  *     http://www.pulse-eight.net/
  32  */
  33
  34 #include "platform/threads/mutex.h"
  35 #include "platform/util/buffer.h"
  36
  37 namespace CEC
  38 {
  39   // a buffer that priotises the input from the TV.
  40   // if we need more than this, we'll have to change it into a priority_queue
  41   class CCECInputBuffer
  42   {
  43   public:
  44     CCECInputBuffer(void) : m_bHasData(false) {}
  45     virtual ~CCECInputBuffer(void)
  46     {
  47       Broadcast();
  48     }
  49
  50     void Broadcast(void)
  51     {
  52       PLATFORM::CLockObject lock(m_mutex);
  53       m_bHasData = true;
  54       m_condition.Broadcast();
  55     }
  56
  57     bool Push(const cec_command &command)
  58     {
  59       bool bReturn(false);
  60       PLATFORM::CLockObject lock(m_mutex);
  61       if (command.initiator == CECDEVICE_TV)
  62         bReturn = m_tvInBuffer.Push(command);
  63       else
  64         bReturn = m_inBuffer.Push(command);
  65
  66       m_bHasData |= bReturn;
  67       if (m_bHasData)
  68         m_condition.Signal();
  69
  70       return bReturn;
  71     }
  72
  73     bool Pop(cec_command &command, uint16_t iTimeout)
  74     {
  75       bool bReturn(false);
  76       PLATFORM::CLockObject lock(m_mutex);
  77       if (m_tvInBuffer.IsEmpty() && m_inBuffer.IsEmpty() &&
  78           !m_condition.Wait(m_mutex, m_bHasData, iTimeout))
  79         return bReturn;
  80
  81       if (m_tvInBuffer.Pop(command))
  82         bReturn = true;
  83       else if (m_inBuffer.Pop(command))
  84         bReturn = true;
  85
  86       m_bHasData = !m_tvInBuffer.IsEmpty() || !m_inBuffer.IsEmpty();
  87       return bReturn;
  88     }
  89
  90   private:
  91     PLATFORM::CMutex                    m_mutex;
  92     PLATFORM::CCondition<volatile bool> m_condition;
  93     volatile bool                       m_bHasData;
  94     PLATFORM::SyncedBuffer<cec_command> m_tvInBuffer;
  95     PLATFORM::SyncedBuffer<cec_command> m_inBuffer;
  96   };
  97 };